Rewrite ${((9^{7})(4^{-6}))^{10}}$ in the form ${9^n \times 4^m}$.
Explanation: ${ ((9^{7})(4^{-6}))^{10} = (9^{(7)(10)})(4^{(-6)(10)})} $ ${\hphantom{ ((9^{7})(4^{-6}))^{10}} = 9^{70} \times 4^{-60}} $